ABSTRACT: Core 3 ? Pilot, Mentoring, and Professional Development Core The Center for Complex Data to Knowledge in Drug Abuse and HIV Behavioral Science (CD2K Center) is committed to fostering the development of the current and next generations of scientists who will advance methods for drug abuse and HIV research, ultimately ensuring that methodological advances improve drug abuse and HIV research for generations to come. The Pilot, Mentoring, and Professional Development Core (PMPD Core) will serve as a resource for the entire CD2K Center, leveraging its intellectual resources to provide mentoring and career development for scientists in the field of quantitative methods for drug abuse and HIV research. The Specific Aims of the PMPD Core are as follows. (1) To administer a successful program of pilot projects that help establish the careers of scientists who are new to quantitative methods for drug abuse and HIV intervention research. This program will facilitate innovative, quantitatively focused research in drug abuse and HIV by awarding and mentoring recipients of competitive pilot projects led by (a) early career scientists who are interested in developing a research program focused on the integration of methodology and drug abuse or HIV research and (b) established scientists in other disciplines, including engineering, computer science, and public health, who wish to refocus their work around methods that are critical to advancing drug abuse and HIV research. (2) To mentor scientists at all levels to foster the development of emerging leaders in drug abuse and HIV intervention methodology. This will be achieved through a combination of formal and informal mentoring activities. CD2K Center investigators will serve as mentors and dissertation advisors for promising graduate students interested in quantitative methods for drug abuse and HIV research, postdoctoral trainees and early career scientists as they begin their transition to independence, and more established scientists from other disciplines who wish to develop a line of research related to drug abuse and HIV. (3) To provide a comprehensive set of professional development opportunities designed to meet the needs of CD2K Center scientists at a variety of levels. This will be accomplished by providing formal and informal educational opportunities, scientific writing labs, data analysis ?hackathons,? and special interest group meetings. In addition, early career scientists can participate in our semester-long professional development series and our annual grant-writing ?boot camp? focused on writing proposals to NIH. All CD2K Center investigators, including established scientists, will benefit from the ongoing research seminars, goal-setting exercise at the business administrative meetings, and education on the responsible conduct of research. The proposed set of structured professional development activities will help ensure that all CD2K Center research is innovative and high- quality, and that it is conducted with the highest level of responsibility.